This walk is a strenuous circular hike over four Donalds, Culter Fell, Gathersnow, Hillshaw Head and Hudderstone hills. There can be breathtaking views across and along along the Clyde Valley.
Terrain: Single-track road, hill and moorland tracks and paths, some pathless sections. Several steep ascents and descents.
Distance: 19 km, duration 7 hrs, total ascent 940m to max ht. 748m.
Start point: Lay-by beside Culter Allers Farm.
Distance / time from Helensburgh: 74 miles / 1hr 30 mins
OS Map Landranger 72 / Explorer 336, Grid ref: NT 032313.